Centrifugal manufacture of reenforced-concrete pipes and the like



Jul 1, 1924. 1,499,762

. H. CONRADI CENTRIFUGAL MANUFACTURE OF REENFORCED CONCRETE PIPES ANDTHE LIKE Filed Jan. 15. 1924 Harr Conrad/ |NVENTOR;

4 Attorney.

Patented daily 11, 192%.

UhliTEfi STATEg HARRY CONRADI, 0F TOORAK, AUSTRALIA.

GEN'IBIFUGAL MANUFACTURE OF .REENFORGED-GONCRETE PIPES AND THE m.

Application filed January 15, 1924. Serial No. 686,279.

To all whom it may concern:

Be it known that I, HARRY CONRADI, a subject of the King of GreatBritain and Ireland, residing at 1A Woodside Crescent, Toorak, in theState of Victoria, Commonwealth of Australia, have invented certain newand useful Improvements in the Centrifugal Manufacture of ReenforcedConcrete Pipes and the Like; and I do hereby declare the following to bea full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

This invention relates to the production centrifugally of reenforcedconcrete pipes and like articles of plastic material. In many such ipeshitherto made the reinforcement is embedded undulyeccentrically, anddoes not ensure sufiicient strength and durability, but my pipes havenot that defect, and will resist hi h pressures and heavy stresses.

This escription refers to a pipe by way of example, and similarly toconcrete as the plastic material. One feature of my invention is thatthe reinforcement is temporarily held in correct position for becomingembedded by the concrete, the temporary holding means bein removed whenthe concrete holds the rein orcement by partly embedding it. Thereinforcement will then be, when desired, concentric or nearly so withinthe mould. By adding concrete within the partly made pipe and usingcentrifu al motion, the reinforcement will then ecome fully embedded,and the pipe will be interiorily thickened to any extent desired.

To carry this invention into effect suitable known means will be used bywhich to apply centrifugal motion to the concrete.

For brevity I refer hereinafter to the reinforcement as a cage; it mayconsist of, and is herewith illustrated as of, spirally wound and ionitudinal wires. It will have any desired iameter and dimensionsaccording to the concrete body to be made. I use for holding the cage,means {termed a core) positioned longitudinally within the ca e. Myconstruction will now be described relatively to the accompanyingdrawings, but some of the details shown may be 1:"; odified whileretaining any matter hereinafter claimed. These drawings are partlydiagrammatic.

Figure 1 is a longitudinal sectional plan of parts of a mould, cage, andcore ready for rotation and reception. of ccncrete.

Figure 2 isan end elevation partly in vertical section of theconstruction in Figure 1.

Figure 3 is a perspective view of part of a core bar.

Figure 4 shows in vertical section a frag ment of the mould, and of apartly completed pipe and part of the cage, without the core.

Figure 5 shows in vertical section a fragment of a completed pipe, withthe cage embedded.

The core contains a plurality of spaced apart, longitudinal adjustableouter members 1 of bar form, and broadening inwardly. I show four barsextending along the mould interior.

2 is a mould, and 3 is part of a cage, one of spirally wound wire beingshown with, at intervals along the cage, bearing rings 3, and atintervals circumferentially' longitudinal rods 3". Each end of the mouldcarries a known ring 4. These rings act as stops at the ends of corebars 1, which have recesses 1 in which a ring 4; fits.

The core bars can be retracted to inner positions, but in their outerpositions shown by Figure 1, each bar bears against the cage interior,holding the cage, temporarily in place prior to the introduction of theconcrete.

The core bars have pivoted to them links 5, 5 which move inpairs, and tofacilitate such pivoting I provide lugs 1 on the bars.

Suitable links 5 have inner ends connected pivotally to slidable members6, hereinafter termed sleeves, while other suitable links 5 have innerends connected to a longitudinal central member 8 shown as a tubularspindle. The sleeves 6 enclosethe stem 8, and are connectedlongitudinally by rods 7, so that the sleeves and connecting rods slideas one. To facilitate pivoting links 5* to the sleeves the latter havelugs 6*. To facilitate connection of ends of rods 7 to sleeve members Irovide any suitablelugs 6 carried byglan' mem- 5 be swung on theirpivots, and will shift bars 1 outwardly or inwardly. 1n the former casethe bars Will be caused to press the cage interiorso as to securely andcorrectly hold it in the mould for rotation purposes. @n the core barsare lugs l which, during the said pressure, meet the mould interior,:preventing the bars being located too near the mould, and preventin. thecage approaching the mould so as to come eccentric thereto, unlessnegligibly.

I prefer that the core bars have recesses 1 in which Will fit cage rings3*. 3 shows a part of the cage displaced to clear a lug i Thus the barsare made to hold'the cage When required concentrically Within the mould.

9 is a nut having rotation means 9, and having a retaining collar 9lined to a sleeve member 6, the nut being mounted on a screw threadedend 8 of stem 8. Rotation of nut 9 causes the stem to move lugs 8 andlinks 5, whereby links 5 are also moved, and the bars 1 are set inwardtowards or outward "from the central stem.

When a cage is held concentrically as describedin a mould, centrifugalmotion Will, when concrete is supplied, cause the concrete toconsolidate against the mould interior, and extend from the mould to thecane, and firmly hold the latter to form a tu' ular shell 12 01"" thethickness indicated in igure 4, or thicker. Then by the described meansthe core bars 1 will be retracted towards stem 8, and the core Will beremoved from the cage. Then the shell 12 is made thiclrer by introducingfurther con crete and applying centrifugal til the desired pipethickness has been produced, indicated at 12.

It is not a part of this invention to finish the pipe surfaces, but itsmooth finish be required suitable known methods are available.

What I claim is:

1. ln the manufacture or reentorced concrete articles, holding areinforcing cage concentrically in a mould by pressure of longitudinaladjustable members of bar type of a core, forming a concrete shellWithin the mould by centrifugal motion so that the shell maintains thecage in the said position, retracting the core members, adding concrete,and applying centrifugal motion, thereby embedding the cage tothe'extent required.

2. A core for temporarily holding a reinforcing; cage concentricallyWithin a mould motion, un

incense to allow of embedding the cage in concrete by centrifugalmotion, the core having a plurality of adjustable longitudinal be withmeans to bear against the mould, and means to bear against the cage, theham being connected to central means Which is justable to move the barsinto expanded or retracted position.

8. A core for temporarily holding reinforcing cage concentrically Withina mount to allow of embedding the cage in concrete by centrifugalmotion, the core having a plu rality of adjustable longitudinal bars emeans to bear against the mould, and to bear against the cage, the barsbeing connected by pivoted arms to a central adjt. t ble stem, and byother pivoted arms to devices near the stem, and relatively to which thestem is movable, whereby the bars be moved into expanded or intoretracted position.

4-. A core for temporarily holding a re" forcing cage concentricallyWithin a motto allow of embedding the cage in concrete by centrifugalmotion, the core having a n rality of adjustable longitudinal bars W nmeans to bear against the mould, and means to bear against the cage, thebars being cc nected by pivoted arms to a central adjus ble stem, and byother pivoted armsvvhi connect the bars to stem enclosing sleeves whichare connected to one another, the es tral stem being movable relativelyto sleeves and having means for longitudin adjusting it to causemovement of the co e bars outwardly to the cage, or invva-i c therefrom.

5. For centri'fugally moulding reenforcei 1 concrete articles, a tubularmould, a cave therein, a core having longitudinal bars l spective partsof which press outvvad against the mould and against the cage, d holdthenlatter concentrically in the moul central stem, connected sleevesprotected glands enclosing the stem, pivoted links connecting thelongitudinal bars and the s pivoted links connecting the longitudi barsand the sleeves, and screvv devices i longitudinally adjusting the stemrelatively to the sleeves, thereby adjusting the said longitudinal bars.

1 ln Witness whereof l have hereunto set my nand.

CQN'RAlDlI Witness:

G-noncn G. inliar.

